Q5 Excess zinc carbonate is added to hydrochloric acid in the preparation of zinc chloride salt. (i) Write an ionic equation for the reaction.
(ii) Why excess zinc carbonate is used?
(iii) Briefly explain how the zinc chloride crystals can be obtained.
Answer
i) ZnCO3(S) + 2HCl(aq) ---> ZnCl2(aq) + H2O(L) + CO2(g)
ionic equation: ZnCO3(s) + 2H(+)(aq)---> Zn(2+)(aq) H2O(L) +CO2(g)
ii) to ensure that the hydrochloric acid is completely reacted.
iii) After the hydrochloric acid is comepletely reacted, filter the excess zinc carbonate, heat the filtrate till little amount is left for crystalization and lastly let it cool down and crystals will be form.

Q4 Sulfuric acid is titrated with potassium hydroxide in the preparation of potassium sulfate salt.
  (i) Explain why this method is recommended for the preparation for this salt. 
(ii) Write an ionic equation for the reaction.
Answers
i) It is a group(I) salt and it is soluble.
ii) H2SO4(aq) + 2KOH(aq)----> k2SO4(aq) + 2H2O(L)
  Ionic equation:   2H(+) (aq) + 2OH(-) (aq) ---> 2H2O(L)

Q3 An unknown green solution is heated with a piece of aluminium foil and sodium hydroxide solution.
  (i) The gas produced turns damp red litmus paper blue. Name the gas evolved.
 (ii) This is a confirmatory test for an anion. Name this anion.
(iii) Give a possible cation which gives the green solution.
Answers
i) ammonia
ii)Nitrate
iii)iron(III)

Q2 Ammonium sulfate is heated with sodium hydroxide.
 (i) Write a chemical equation (include state symbols) for the reaction.
 (ii) Describe a test for the gas.
answers
i)(NH4)2SO4 (aq) + 2NaOH(aq)---> Na2SO4(aq)+2H2O(l)+2NH3(g)
ii)Place a piece of damp red litmus paper above the reacting solutions

Q1 Zinc nitrate reacts with aqueous ammonia (NH4OH) to form a salt and a base.
  (i) Name the salt and the base.
 (ii) Describe the observations for the reaction.
(iii) Write a chemical equation for the reaction (include state symbols).
(iv) Write an ionic equation for the reaction.
Answers 
I) the salt is ammonium nitrate and the base is zinc hydroxide
ii) white solution is form when they are mixed together.
iii)ZnNO3(aq) +NH4OH(aq)-->ZnOH(s)+NH4NO3(aq)
iv)Zn+(aq) + OH-(aq)-->ZnOH(s)